Epson 7900 sharper than 2400 ?

[PhR]

I usually print on Hahnmuehle Photo Rag with an Epson 2400 and I sometimes send images to a professional in order to print larger sizes on a 7900 on the same paper.

Before doing this, I tune the sharpening on my 2400 by printing parts of the image at the size they will have with the 7900. I use the 3 pass method described in the Fraser/Schewe book and I send a sharpened .tiff/16bits file to the third-party and ask for a raw printing: please do not change anything to the image, just use the right profile and print.

However, it appears that the output from the 7900 is notably sharper that what I have with my tests. Like if someone has applied a radius 1, amount 150% additional sharpening before printing (the pixels density is about 200 dpi). The guy says that it is not the first time that someone is surprised by the "extra sharpening" of its 7900.

I've never heard of such a difference. Since the guy has this printer recently, I was wondering if the difference could be due to a (wrong ?) configuration setting in the 7900 driver. I would appreciate if someone here could enlight me.

Thanks

Philippe

[Ernst Dinkla]

Minimum droplet size for both printers is 3.5 picoliter, I doubt that the 7900 improved weaving/dithering results in a higher sharpness.

The smart print sharpening setting in applications like Lightroom or Qimage Ultimate can be overdone. I guess some RIPs will have that feature too and can be misused.

It would be worse and against your request if there is also an extra sharpening done by the print shop before the printing stage.

If none of both was applied (though some smart print sharpening should in theory) then you possibly see better upsampling routines in the print shop's print. That and selecting Fine Detail in the driver so the driver asks for 720 PPI may make a difference + the slower print speed then which should create less dot gain. I am not familiar with the 7900 results to say that it should make that difference. My bet is the smart print sharpening overdone.


--
Met vriendelijke groet, Ernst

Dinkla Grafische Techniek
Quad,piëzografie,giclée
www.pigment-print.com

[Wayne Fox]

The  7900 does supposedly have more accurate dot placement.  Seems unlikely to translate to something more visually sharp ...

[PhR]

Thanks Ernst and Wayne for your useful comments. I've installed the 7900 driver on my machine and I can see a "Fine Detail" option that could add some sharpening - it is recommended for text printing. I am going to check the configuration of the driver the guy uses and this option in particular.

Philippe

[Snoopy Lane]

I found this article by Jeff Schewe just today: The Right Resolution.  He's got some recommendations about the Fine Detail option.

[Wayne Fox]

Thanks Ernst and Wayne for your useful comments. I've installed the 7900 driver on my machine and I can see a "Fine Detail" option that could add some sharpening - it is recommended for text printing. I am going to check the configuration of the driver the guy uses and this option in particular.

Philippe

I thought the issue was the 7900 was "sharper" than the 2400, not that it wasn't sharp enough?

After thinking about it, the 7900 dot placement and dithering is substantially superior to that of the 2400 ... and I do think it could easily translate into the appearance of a "sharper" image.  The 2400 is pretty old technology against the latest and best and the head in the 7900 is vastly superior at laying down ink than the 2400. This would only be obvious on close examination ...

I think if you want to fine tune sharpening, you would be better off printing test strips on the 7900 itself ...

[PhR]

An update on this topic : the culprit was the quality set to 2880 dpi and the "Fine detail" option on. Both where creating artifacts of oversharpening (at least on the PhotoRag). Once back to 1440 dpi (as recommended by the paper manufacturer) and "Fine detail" option desactivated, the resulting sharpness of the image is almots identical to the one I get from the 2400 and I can still use it for "pre-proofing" sharpening.

Thank you for your help and for the useful articles references.

Philippe